JP2008298564A - Manufacturing method for roll bearing unit equipped with physical quantity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a manufacturing method capable of suppressing the manufacturing cost by simplifying preparations, while dispensing with a device which applies a known axial load for suppressing the manufacturing cost. <P>SOLUTION: A computer computes physical quantity on the basis of outputted signals of a sensor, based on the gain and the zero-point stored in a memory. The gain among them is the relation, between the degree of change in outputting signals and the degree of change in physical quantity. Such characteristics relating to the roll bearing unit which influence the gain are measured, in a state with the single roll bearing being stored. Then these records are stored in the memory of the computer which constitutes the physical quantity measuring device, combined with the roll bearing unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  A physical quantity measuring device for a rolling bearing unit that is an object of the present invention measures a physical quantity such as an external force that acts between a stationary side race ring such as an outer ring and a rotary side race ring such as a hub that constitutes the rolling bearing unit. Use to do. Further, the obtained physical quantity is used for ensuring the running stability of a vehicle such as an automobile. The present invention is intended to reduce the manufacturing cost of such a physical quantity measuring device for a rolling bearing unit.

  For example, automobile wheels are rotatably supported by a suspension device by a double-row angular type rolling bearing unit. In order to ensure the running stability of automobiles, for example, anti-lock braking system (ABS), traction control system (TCS), and electronically controlled vehicle stability control system (ESC) etc. The device is in use. In order to control such various vehicle running stabilization devices, signals representing the rotational speed of the wheels, acceleration in each direction applied to the vehicle body, and the like are required. In order to perform higher-level control, it may be preferable to know the magnitude of a load (for example, one or both of a radial load and an axial load) applied to the rolling bearing unit via a wheel.

  In view of such circumstances, Patent Document 1 describes an invention in which a special encoder is used to measure the magnitude of a load applied to a rolling bearing unit. 6 to 8 show a first example of a conventional structure relating to a physical quantity measuring device for a rolling bearing unit, which employs the same load measurement principle as the structure described in Patent Document 1. FIG. The first example of this conventional structure is a hub 2 that is a rotating side race ring that rotates with the wheel while being supported and fixed to the inner diameter side of the outer race 1 that is a stationary side race ring that does not rotate even when used. Is rotatably supported via a plurality of rolling elements 3 and 3. A preload is applied to each of the rolling elements 3 and 3 together with a contact angle of the rear combination type. In the illustrated example, balls are used as the rolling elements 3 and 3. However, in the case of an automobile bearing unit that is heavy in weight, a tapered roller may be used instead of the ball.

  Also, the inner end of the hub 2 ("inner" in the axial direction means the center in the width direction of the vehicle when assembled to the automobile, and is the right side of FIGS. 6, 9, 10 and 12. Conversely, to the automobile. 6, 9, 10, 12, which is the outer side in the width direction of the vehicle in the assembled state of FIG. 6, is referred to as “outside” with respect to the axial direction. The hub 2 is supported and fixed concentrically. In addition, a sensor holder 7 in which a pair of sensors 6a and 6b are embedded is held inside a bottomed cylindrical cover 5 that closes the inner end opening of the outer ring 1, and a detection unit for both the sensors 6a and 6b. Is placed in close proximity to the outer peripheral surface which is the detected surface of the encoder 4.

  Of these, the encoder 4 is made of a magnetic metal plate. Through holes 8 and 8 and column portions 9 and 9 (see FIG. 7) are alternately arranged in the circumferential direction in the first half (the inner half in the axial direction) of the outer circumferential surface of the encoder 4, which is the detected surface. And at equal intervals. The boundaries between the through holes 8 and 8 and the pillars 9 and 9 are inclined by the same angle with respect to the axial direction (width direction) of the detection surface, and the inclination direction with respect to the axial direction is determined by the detection target. The directions are opposite to each other with the axial middle portion of the surface as a boundary. Accordingly, each of the through holes 8 and 8 and each of the column portions 9 and 9 has a "<" shape with an axially intermediate portion protruding most in the circumferential direction. And among the axially outer half part and the axially inner half part of the detected surface, the boundary inclination directions are different from each other, the axially outer half part is defined as the first characteristic changing part 10, and the axially inner half part Is the second characteristic changing unit 11. In addition, each through-hole which comprises both these characteristic change parts 10 and 11 may be formed in the mutually continuous state like illustration, and it forms in the mutually independent state (each through-hole is made into "C" shape. Arrangement).

  The cover 5 is formed in a bottomed cylindrical shape entirely by a metal plate such as a stainless steel plate, and is fitted and fixed to the inner end of the outer ring 1. Both the sensors 6a and 6b are held and fixed in such a cover 5 via the sensor holder 7 made of synthetic resin. Each of the sensors 6a and 6b is composed of a permanent magnet and a magnetic detection element such as a Hall IC, a Hall element, an MR element, and a GMR element constituting a detection unit. The two sensors 6a and 6b are embedded in a part (for example, the lower end) of the sensor holder 7, and the detection unit of one sensor 6a is used as the first characteristic changing unit 10 and the other sensor 6a and 6b is embedded in the other. The detection part of the sensor 6b is made to face and oppose the second characteristic change part 11 respectively.

  The positions where the detection units of both the sensors 6 a and 6 b face both the characteristic change units 10 and 11 are the same in the circumferential direction of the encoder 4. Further, in the neutral state where no axial load is applied between the outer ring 1 and the hub 2, the axially intermediate portions of the through holes 8, 8 and the column portions 9, 9 are projected most in the circumferential direction. The position of each member is regulated so that a portion (a portion where the tilt direction of the boundary changes) is located at the center position between the detection portions of the sensors 6a and 6b.

  In the case of the physical quantity measuring device for a rolling bearing unit configured as described above, when an axial load acts between the outer ring 1 and the hub 2 (the outer ring 1 and the hub 2 are relatively displaced in the axial direction (axial direction)). The phase at which the output signals of the sensors 6a and 6b change is shifted. That is, in the neutral state where no axial load is applied between the outer ring 1 and the hub 2, the detecting portions of the sensors 6a and 6b are on the solid lines A and B in FIG. It faces a portion that is shifted by the same amount in the axial direction from the most protruding portion. Therefore, the phases of the output signals of the sensors 6a and 6b coincide as shown in FIG.

  On the other hand, when a downward axial load is applied to the hub 2 to which the encoder 4 is fixed as shown in FIG. 8A, the detecting portions of the sensors 6a and 6b are shown in FIG. , Opposite to the portions where the deviations in the axial direction from the most protruding portion are different from each other. In this state, the phases of the output signals of the sensors 6a and 6b are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 2 to which the encoder 4 is fixed as shown in FIG. 8A, the detecting portions of both the sensors 6a and 6b are connected to the chain line H shown in FIG. , C, that is, the deviation in the axial direction from the most projecting portion opposes different portions in the opposite direction. In this state, the phases of the output signals of the sensors 6a and 6b are shifted in the opposite direction to the case of (B), as shown in (D) of FIG.

  As described above, in the case of a conventionally known physical quantity measuring device for a rolling bearing unit as described in Patent Document 1, the phases of the output signals of both the sensors 6a and 6b are the same as those of the outer ring 1 and the hub. 2 is shifted in a direction corresponding to the direction of action of the axial load applied between the outer ring 1 and the axial direction of the outer ring 1 and the hub 2. Further, the degree of the phase shift of the output signals of the sensors 6a and 6b due to the axial load (relative displacement) increases as the axial load (relative displacement) increases. Therefore, based on the presence and absence of the phase shift of the output signals of the sensors 6a and 6b and the direction and magnitude of the shift, each is a physical quantity between the outer ring 1 and the hub 2. The direction and magnitude of the relative displacement in the axial direction, and the direction and magnitude of the axial load are obtained.

  Note that such processing for calculating an axial load, which is a kind of physical quantity, is performed by a calculator (not shown). For this reason, in the memory of this computing unit, a phase difference (which changes according to the output signal), which is a phase difference between the output signals of the two sensors 6a and 6b, which has been examined in advance by theoretical calculation or experiment. Value) and the relative displacement in the axial direction or the axial load is stored as a relational expression or a map type. This relationship includes the gain that is the relationship between the degree of change of the phase difference and the amount of change of the axial load, and the value of the phase difference when the value of the axial load is zero. There is a zero.

  In the case of the above-described first example of the conventional structure, the through holes 8 and 8 and the column portions 9 and 9 are alternately arranged on the detection surface of the encoder 4, and the characteristics of the detection surface are alternately set. And it is changed at equal intervals. On the other hand, as shown in FIG. 9, a physical quantity measuring device for a rolling bearing unit including an encoder 4a made of a permanent magnet, in which S poles and N poles are alternately arranged on the outer peripheral surface which is a detection surface, It is described in Patent Document 2 and the like and has been conventionally known. The basic structure and operation of the physical quantity measuring apparatus for the rolling bearing unit shown in FIG. 9 are the same as those in the first example of the conventional structure shown in FIGS. However, in the case of the second example of the conventional structure shown in FIG. 9, since a permanent magnet is provided on the encoder 4a side, in principle, if a magnetic detection element is provided on the sensor 6a, 6b side. Good, no permanent magnet is needed. Further, in the case of the structure shown in FIG. 9, a caulking portion formed at the inner end in the axial direction of the hub body is used in place of the nut shown in FIG. It is done by. However, such a structure has been conventionally known and is not related to the gist of the present invention.

  Furthermore, Patent Document 3 describes a physical quantity measuring device for a rolling bearing unit as shown in FIGS. First, in the case of the third example of the conventional structure shown in FIGS. 10 to 11, a slit-shaped transparent portion is formed on the tip half of a cylindrical encoder 4 b made of a magnetic metal plate and fitted and fixed to the inner end of the hub 2. The holes 8a and 8a and the pillar portions 9a and 9a (see FIG. 11) are alternately arranged at equal intervals in the circumferential direction. The boundaries between the through holes 8a and 8a and the pillars 9a and 9a are linear shapes that are inclined by the same angle in the same direction with respect to the axial direction of the encoder 4b. Further, the detection portions of the pair of sensors 6a and 6b supported and fixed to the inner end portion of the outer ring 1 via the cover 5 and the sensor holder 7 are arranged on the upper and lower sides of the outer peripheral surface of the front half of the encoder 4b, which is the detection surface. The two positions (the portions in which the circumferential phases are different from each other by 180 degrees) are placed close to each other.

  In the case of a rolling bearing unit for supporting a wheel of an automobile, an axial load applied between the outer ring 1 and the hub 2 is input from a ground contact surface between a tire outer peripheral surface and a road surface constituting a wheel coupled and fixed to the hub 2. Is done. Since this ground contact surface exists radially outward from the rotation center of the outer ring 1 and the hub 2, the axial load is not between the outer ring 1 and the hub 2 but as a pure axial load. 1 and the center axis of the hub 2 and the center of the grounding surface are applied with a moment in a virtual plane (in the vertical direction). When such a moment is applied between the outer ring 1 and the hub 2, the central axis of the hub 2 is inclined with respect to the central axis of the outer ring 1. Accordingly, the upper end of the encoder 4b is displaced in any direction with respect to the axial direction, and the lower end is similarly displaced in the opposite direction. As a result, the phases of the output signals of the sensors 6a and 6b, in which the detection units are placed close to and opposed to the upper and lower ends of the outer peripheral surface of the encoder 4b, are shifted in the opposite directions with respect to the neutral position. Therefore, the direction and magnitude of the axial load can be obtained based on the direction and magnitude of the phase shift between the output signals of both the sensors 6a and 6b.

  Furthermore, in the case of the fourth example of the conventional structure shown in FIGS. 12 to 13, a through hole 8 b is formed in the tip half of a cylindrical encoder 4 c made of a magnetic metal plate that is externally fitted and fixed to the inner end of the hub 2. 8b and column portions 9b and 9b (see FIG. 13) are alternately arranged at equal intervals in the circumferential direction. Each of these through holes 8b, 8b has a trapezoidal shape when viewed from the radial direction, and gradually changes the width dimension in the circumferential direction with respect to the axial direction. Further, the detection portion of one sensor 6 supported and fixed to the inner end portion of the outer ring 1 via the cover 5 and the sensor holder 7 is brought close to and opposed to the outer peripheral surface of the front half of the encoder 4c, which is the detected surface. ing. In the fourth example of the conventional structure configured as described above, when the outer ring 1 and the hub 2 are relatively displaced in the axial direction based on the axial load, the duty ratio of the output signal of the sensor 6 (high potential duration / 1 cycle) changes. Therefore, the magnitude of the relative displacement and further the magnitude of the axial load can be obtained based on the duty ratio.

  In the case of the first and second examples of the conventional structure shown in FIGS. 6 to 9 described above, a pair of sensors 6a in which the respective detection units are opposed to the first and second characteristic change units 10 and 11, respectively. , 6b, only one set is provided. In contrast, although not shown in the drawings, Patent Document 3 and Japanese Patent Application No. 2006-345849 each have a structure in which a plurality of sensor sets each including a pair of sensors are provided so that multidirectional displacement or external force can be obtained. Is described.

  The above-described conventionally known rolling bearing unit with a physical quantity measuring device, such as an external force such as an axial load, which acts between a stationary raceway such as the outer ring 1 and a rotary raceway such as the hub 2. In order to measure the physical quantity, it is necessary to know the relationship between the sensor output signal and the physical quantity, that is, the zero point and gain related to the relation between the output signal and the physical quantity. For example, in the first to third examples of the conventional structure shown in FIGS. 6 to 9, the phase difference ratio of the pair of sensors 6a and 6b (= phase difference between output signals of both the sensors 6a and 6b / 1 period) Regarding the relationship with the axial load, know the phase difference ratio (zero point) when this axial load is zero, and the displacement amount (gain) of this phase difference ratio when this axial load changes by a unit amount. It is necessary to keep. 12 to 13, the duty ratio (zero point) when the axial load is zero and the displacement (gain) of this duty ratio when the axial load changes by a unit amount are also shown in FIGS. I need to know.

Therefore, conventionally, as described in Patent Document 4, a known axial load is applied between the hub and the outer ring while rotating the hub constituting the rolling bearing unit with a physical quantity measuring device after assembly is completed. Then, it is considered to measure the output signal of the sensor and obtain the relationship (zero point and gain) between these axial loads and the output signal. The obtained zero and gain are stored in the memory of the arithmetic unit for obtaining the axial load via a wireless IC tag or the like. In the case of such a conventional method for obtaining the zero and gain, the cost of the manufacturing apparatus increases instead of obtaining the zero and gain with high accuracy. This is because it is necessary to provide a device that applies a known axial load between the hub and the outer ring while rotating the hub constituting the rolling bearing unit with a physical quantity measuring device after assembly is completed. In addition, after completing the assembly of the rolling bearing unit with a physical quantity measuring device at the manufacturing factory of the rolling bearing unit with a physical quantity measuring device, the work for obtaining the zero point and the gain before entering the product enters the rolling bearing unit with the physical quantity measuring device. The setup for manufacturing the bearing unit deteriorates. These increase the manufacturing cost of the rolling bearing unit with a physical quantity measuring device.
As publications related to the present invention, there are Patent Literatures 5 to 8 and Non-Patent Literature 1.

JP 2006-1113017 A JP 2006-317420 A JP 2007-93580 A JP 2007-194673 A Japanese Patent Laid-Open No. 5-10835 JP-A-6-344233 JP 2000-74788 A JP 2002-263969 A NSK Report, NSK Ltd., November 1989, p. 59-66

  In view of the circumstances as described above, the present invention eliminates the need for a device that applies a known axial load, thereby reducing the cost of the manufacturing device, simplifying the setup, and reducing the manufacturing cost of the rolling bearing unit with a physical quantity measuring device. The present invention has been invented to realize a manufacturing method.

A rolling bearing unit with a physical quantity measuring device, which is an object of the manufacturing method of the present invention, includes a rolling bearing unit and a physical quantity measuring device.
Of these, the rolling bearing unit includes a stationary-side bearing ring, a rotating-side bearing ring, and a plurality of rolling elements. Of these, the stationary-side raceway has a double-row stationary-side raceway on the stationary-side peripheral surface, and does not rotate during use. The rotation-side raceway has a double-row rotation-side raceway on the rotation-side circumferential surface facing the stationary side circumferential surface in the radial direction, and rotates when in use. Further, each of the rolling elements is provided between the rotation-side tracks of both rows and the stationary-side tracks of both rows so as to be freely rollable in a state where a preload is applied to each row. ing.

On the other hand, the physical quantity measuring device includes an encoder, at least one sensor, and a calculator.
Of these, the encoder is supported and fixed concentrically with the rotation-side raceway by a part of the rotation-side raceway or a rotation member coupled and fixed concentrically with the rotation-side raceway. And a concentric surface to be detected. The characteristics of the detected surface are alternately changed in the circumferential direction.
The sensor is supported by a non-rotating portion in a state where the detection unit faces the detection surface of the encoder, and changes an output signal in response to a change in characteristics of the detection surface.
Further, the computing unit acts on the relative displacement between the stationary side raceway and the rotation side raceway and between the stationary side raceway and the rotation side raceway based on the output signal of the sensor. It has a function of calculating at least one physical quantity of the external force.

  In order to manufacture such a rolling bearing unit with a physical quantity measuring device, in the case of the manufacturing method according to claim 1, the arithmetic unit is used when calculating the physical quantity based on an output signal of the sensor. The characteristics of the rolling bearing unit that affect the gain, which is the relationship between the degree of change of the output signal or the value that changes in accordance with the output signal, and the degree of change of the physical quantity, Measure in a single state (meaning that measurement is performed without using a physical quantity measuring device, and the physical quantity measuring device and the rolling bearing unit may be combined during the measurement work) and record. And this record is recorded in the memory of the arithmetic unit which comprises the said physical quantity measuring apparatus combined with the said rolling bearing unit.

When the invention described in claim 1 as described above is carried out, for example, as in the invention described in claim 2, the characteristic relating to the rolling bearing unit that affects the gain is the rigidity of the rolling bearing unit. . Then, by recording this rigidity or data related to this rigidity in the memory of the calculator, the gain used by this calculator corresponds to the rigidity of the rolling bearing unit.
Alternatively, as in the third aspect of the present invention, the characteristic relating to the rolling bearing unit that affects the gain is the preload of the rolling bearing unit. Then, by recording this preload or data related to this preload in the memory of the calculator, the gain used by this calculator corresponds to the preload of the rolling bearing unit.
When the invention described in claim 3 is carried out, as described in claim 4, for example, the preload is obtained based on the initial clearance of the rolling bearing unit.

The invention described in claims 1 to 4 records the gain corresponding to the characteristics in the memory of the arithmetic unit without adjusting the characteristics of the rolling bearing unit. In this case, the characteristics of the rolling bearing unit are adjusted in accordance with the gain recorded in the memory of the arithmetic unit.
That is, in the case of the invention described in claim 5, the preload applied to the rolling bearing unit is adjusted. The arithmetic unit used when calculating the physical quantity based on the output signal of the sensor changes the output signal or the value that changes according to the output signal, and the magnitude of the physical quantity changes. The characteristic relating to the rolling bearing unit that influences the gain, which is a relationship with the degree to be performed, is made to coincide with the gain recorded in the memory of the arithmetic unit constituting the physical quantity measuring device.
When the invention described in claim 5 is carried out, for example, as described in claim 6, the preload applied to the rolling bearing unit is adjusted so that each of the rolling elements has a predetermined diameter. This is done by selecting one and installing it between a pair of stationary and rotating tracks.

  In carrying out each of the above-described inventions, preferably, as described in claim 7, after the rolling bearing unit and the physical quantity measuring device are combined, the stationary bearing ring and the rotating bearing ring The sensor output signal is taken into the arithmetic unit in the state where the external force fluctuating in the driving state is not applied and the two race wheels are in the neutral position. Then, the output signal of the sensor in this state is recorded in the memory of the arithmetic unit as a zero point which is the value of this output signal when the physical quantity is in a neutral state.

When carrying out each of the present inventions described above, preferably, as described in claim 8, the rolling bearing unit is a wheel bearing rolling bearing unit for rotatably supporting a wheel on a suspension system of an automobile. And The stationary raceway is an outer ring that is supported and fixed to the suspension device during use, and the rotation-side raceway is a hub that rotates together with the wheel while the wheels are coupled and fixed.
When carrying out such an invention described in claim 8, preferably, as described in claim 9, the rolling bearing unit and the physical quantity measuring device are combined, and the outer ring is supported and fixed to the suspension device. After the wheel is coupled and fixed to the hub, the external force that fluctuates depending on the running state of the vehicle is not applied between the outer ring and the hub while the weight of the vehicle is supported by the wheel on a flat surface. In a state where the outer ring and the hub are in the neutral position, the output signal of the sensor is taken into the arithmetic unit. Then, the output signal of the sensor in this state is recorded in the memory of the arithmetic unit as a zero point which is the value of this output signal when the physical quantity is in a neutral state.

According to the present invention configured as described above, a device for applying a known axial load is not required, the cost of the manufacturing device is reduced, the setup is simplified, and the manufacturing cost of the rolling bearing unit with a physical quantity measuring device is reduced. It is done.
That is, the rigidity of the rolling bearing unit or the preload applied to the rolling bearing unit affects the difficulty of relative displacement between the stationary bearing ring and the rotating bearing ring constituting the rolling bearing unit. Specifically, the higher the rigidity and the greater the preload, the smaller the relative displacement between the stationary side raceway and the rotation side raceway when an external force is applied. In other words, the lower the rigidity and the smaller the preload, the greater the relative displacement between the stationary side raceway and the rotation side raceway when an external force is applied. In the case of rolling bearing units of the same type (with the same model number), even if the rigidity or preload changes to some extent (with no problem in practice and passed by quality inspection as a rolling bearing unit), There is a clear relationship close to a proportional relationship between the preload and the relative displacement. And this relationship can be known beforehand by experiment or analysis.

Therefore, if the rigidity or preload is measured by a single rolling bearing unit, the rigidity or preload, or data related to the rigidity or preload is stored and recorded in the memory of the calculator, A gain, which is a relationship between the degree to which the sensor output signal or a value that changes in accordance with the output signal changes, and the degree to which the physical quantity changes can be input. Then, the degree of change in the physical quantity between the stationary side raceway and the rotation side raceway can be obtained from this gain.
Further, as in the invention described in claim 5, even if the preload of the rolling bearing unit is a value corresponding to the gain stored in the memory of the computing unit, the stationary side race ring and the rotary side raceway are obtained by this gain. The degree of change in physical quantity between the wheels is required.

[First example of embodiment]
The invention according to claims 1 to 3 and 7 to 9 will be described with reference to FIGS. In this example, as shown in FIGS. 6 to 11 described above, an axial acting between the outer ring 1 and the hub 2 by the phase difference ratio existing between the output signals of the pair of sensors 6a and 6b. It shows a case where a structure for obtaining a load is made. In the case of such a manufacturing method of a rolling bearing unit with a physical quantity measuring device of this example, as shown in the flowchart of FIG. 1, first, in step 1 (S1), each component (outer ring 1, After assembling the hub 2, rolling elements 3, 3 etc. (see FIGS. 6, 9, 10 and 12), in step 2 (S2), tighten the nut (in the case of the structure of FIGS. 6, 10 and 12), or By forming the caulking portion (in the case of the structure of FIG. 9), a preload is applied to each rolling element 3, 3. In this state, the rolling bearing unit is completed.

  Then, after assembling the rolling bearing unit while applying a preload to the rolling elements 3 and 3 in this manner, the rigidity of the rolling bearing unit is obtained in step 3 (S3). The work for obtaining the rigidity is described in Patent Documents 5 to 7 and the like, as is well known in the technical field of rolling bearings, vibration is applied to the rolling bearing unit to obtain the resonance frequency of the rolling bearing unit. By doing things. Based on the resonance frequency thus obtained, the preload applied to the rolling bearing unit is obtained. The preload applied to the rolling bearing unit greatly affects the rigidity of the rolling bearing unit, and the rigidity increases as the preload increases. As the rigidity increases, the amount of relative displacement between the outer ring 1 and the hub 2 based on external force decreases. In short, as shown in FIG. 2, the larger the preload applied to the rolling bearing unit, the smaller the relative displacement between the outer ring 1 and the hub 2 based on the axial load, and the smaller the phase difference ratio. From this, it can be seen that the information on the rigidity or preload of the rolling bearing unit can be used as a gain for obtaining the axial load.

  That is, when the preload applied to the rolling bearing unit is large, the rigidity of the rolling bearing unit is increased. Therefore, the phase difference generated between the output signals of the sensors 6a and 6b in the state where the axial load is applied. The variation of the ratio is reduced. On the other hand, as the preload decreases, the rigidity decreases, and the variation in the phase difference ratio based on the axial load increases. Therefore, in order to obtain the axial load with practical accuracy, it is necessary to know the preload or the stiffness that changes based on the preload. If the rigidity is different, the gain that is the relationship between the axial load and the phase difference ratio is different, and this axial load may not be obtained with sufficient accuracy.

For example, when the rigidity of the rolling bearing unit is Ka, the contact angle of each of the rolling elements 3 and 3 constituting the rolling bearing unit is α, and the resonance frequency (natural frequency) of the rolling bearing unit is fa. The rigidity Ka of this rolling bearing unit is
Ka = f (fa, α) --- (1)
Is required.
The preload Fa applied to the rolling elements 3 and 3 is
Fa = f (Ka, α) (2)
Is required.
The method for obtaining the rigidity Ka and the preload Fa of the rolling bearing unit from the resonance frequency as described above is described in Patent Documents 5 to 7, Non-Patent Document 1, etc., and is well known in the technical field of rolling bearing units. Since it is a technology, detailed explanation is omitted.
In any case, since the specifications of the rolling bearing unit are known, if the resonance frequency of the rolling bearing unit can be measured, the rigidity of the rolling bearing unit and further the preload applied to the rolling bearing unit can be estimated. . Then, by using the estimated preload value, the arithmetic unit constituting the rolling bearing unit with a physical quantity measuring device can determine the gain to be used when calculating the axial load based on the phase difference ratio.

  Therefore, information relating to the preload or rigidity of the rolling bearing unit obtained as described above is recorded and attached to the rolling bearing unit (so that it can be sent to the subsequent assembly process together with the rolling bearing unit). The method for attaching the information to the rolling bearing unit is not particularly limited. For example, a label on which the information is printed as a barcode or a two-dimensional barcode, or an electronic component such as an IC tag on which the information is recorded, It is possible to adopt a method of attaching by sticking or thin string, or a method of marking directly on the rolling bearing unit. Further, the information may be the preload itself of the rolling bearing unit, or may be a value that changes (corresponding one-to-one) with respect to the preload, such as rigidity and resonance frequency.

  After obtaining the preload value associated with the gain as described above, in step 4 (S4), the encoders 4, 4a, 4b and the sensors 6a, 6b (see FIGS. 6 to 11) are assembled, 5 (S5), an output test is performed to confirm the output signals of both the sensors 6a and 6b. This output inspection is performed by rotating the hub 2 and outputting signals from both the sensors 6a and 6b. During this output inspection, by checking the phase difference ratio existing between the output signals of both sensors 6a and 6b, the initial phase difference ratio, which is the phase difference ratio when no axial load is applied, is confirmed. To do. Therefore, in step 6 (S6), based on this initial phase difference ratio and the preload or a value that changes in relation to the preload, the zero point and gain when the axial load is calculated based on the phase difference ratio. Create information about.

  In this case, for gain information, a gain map is selected from the information (preload, stiffness, resonance frequency) obtained by measuring the resonance frequency of the rolling bearing unit in step 3 (in this information). Obtained by selecting the corresponding map). The gain map is obtained by obtaining the relationship between the above information (preload, stiffness, resonance frequency) and the gain from the characteristics of the rolling bearing unit, the specifications of the vehicle to be used, etc. in advance by experiment or analysis. Easy to get. As the gain map used in this case, it is conceivable to use information obtained by dividing the information such as the preload into several types of ranges. In this case, division is performed based on experiments or analyzes performed in advance so that errors can be minimized (in as many stages as possible within a range that allows for various types of trouble). Preferably, it is divided into 3 to 10 stages so that the range of each stage is within the range of about 0.98 to 1.96 kN (100 kgf to 200 kgf) as a preload value. While selecting the map corresponding to the above information from the maps divided to this extent and obtaining the gain for calculating the axial load from the phase difference ratio, while ensuring the necessary accuracy, Gain selection is easy.

  On the other hand, the information regarding the zero point is created based on the initial phase difference ratio at the time of the output inspection for confirming the output signals of the two sensors 6a and 6b performed in step 5. In this case, the initial phase difference ratio obtained in the output inspection may be used as the zero point as it is. However, preferably, the initial phase difference ratio is attached to the vehicle, that is, provided between the suspension device and the wheel to add the vehicle weight. The initial phase difference in the state is set to zero. If the initial phase difference ratio in the state where the vehicle weight is applied is set to the zero point, when traveling straight, the zero point is the zero point (if the slight deviation due to the toe angle, camber angle, caster angle, etc. when attached to the vehicle is ignored) ) Almost matches. In addition, in order to make the state in which the vehicle weight is applied to be a zero point, it is conceivable that the vehicle assembled with the rolling bearing unit with a physical quantity measuring device is run straight on a flat road (in this case, the toe angle, the camber angle, The initial phase difference can be obtained in a state including a shift due to the caster angle).

  However, it is troublesome to perform such a thing for each vehicle, which causes an increase in the cost of a vehicle equipped with a rolling bearing unit with a physical quantity measuring device. On the other hand, since the output inspection performed in step 5 is a rotation inspection with no load, there is no difference between the initial phase difference in this inspection and the initial phase difference with the vehicle weight added. (There is a possibility that a difference is present between the outer ring 1 and the hub 2 due to the vehicle weight if the center of action of the vehicle weight and the center of the rolling bearing unit are offset). Therefore, a relationship between the initial phase difference ratio with no load and the initial phase difference ratio with the vehicle weight added is obtained in advance by experiment or analysis, and the initial phase obtained by the output inspection performed in step 5 above is obtained. By calculating the initial phase difference ratio with the vehicle weight applied based on the phase difference ratio, it is easy to determine the initial phase difference ratio while ensuring the required accuracy (without actually driving the vehicle). ) Yes.

As described above, if the zero point and gain for obtaining the axial load are obtained based on the phase difference ratio existing between the output signals of the sensors 6a and 6b, a rolling bearing unit with a physical quantity measuring device is manufactured. In the normal (originally necessary) process, the zero and gain can be obtained. Therefore, the inspection / shipment process can be minimized, and the above-mentioned rolling bearing unit with a physical quantity measuring device can be manufactured at low cost.
In other words, preload management is conventionally performed for the wheel bearing rolling bearing unit, and for the rolling bearing unit with a rotational speed measuring device incorporating an ABS control encoder, the sensor output confirmation has been performed conventionally. This is done in the manufacturing process of the rolling bearing unit with speed measuring device.
And when implementing this invention, a gain can be obtained using the said preload management process, and the said zero point can be obtained using the said output confirmation process. For this reason, unlike the prior art described in Patent Document 4 described above, it is not necessary to prepare a dedicated device and a dedicated process in order to obtain a zero and a gain, and the manufacturing cost of the rolling bearing unit with the physical quantity measuring device is eliminated. Can be reduced.

  The zero point and gain obtained as described above are stored in the memory of the computing unit in step 7 (S7), and completed in step 8 (S8) as a rolling bearing unit with a physical quantity measuring device. In this case, when the arithmetic unit is incorporated in (incorporated into) the rolling bearing unit with a physical quantity measuring device, information on the zero point and the gain is used to manufacture the rolling bearing unit with the physical quantity measuring device. What is necessary is just to memorize | store in the memory of the said arithmetic unit directly at a factory. On the other hand, when the arithmetic unit is installed separately (when a dedicated load calculation unit is provided, or when a CPU for load calculation is mounted on another control unit, such as when it is not in the rolling bearing unit). The zero point and gain need to be read into the arithmetic unit at the automobile assembly plant. Therefore, in such a case, a label on which the above information is printed as a barcode, a two-dimensional barcode, or an electronic component such as an IC tag on which this information is recorded is attached to the rolling bearing unit with a physical quantity measuring device. Or tie with a thin string. Alternatively, it is possible to directly mark the rolling bearing unit.

[Second Example of Embodiment]
The invention according to claims 1, 3, 4, and 6 to 9 will be described with reference to FIGS. In the case of this example as well, as in the first example of the embodiment described above, the phase difference existing between the output signals of the pair of sensors 6a and 6b causes a gap between the outer ring 1 and the hub 2. It shows the case where a structure for determining the acting axial load is made. By knowing the value of the preload applied to the rolling bearing unit (see FIGS. 6, 9, 10, and 12), the axial load is determined based on the phase difference ratio existing between the output signals of the sensors 6a and 6b. Obtaining the zero point and gain for obtaining is the same as in the first example of the above embodiment. Therefore, the description regarding the same part as the first example will be omitted or simplified, and the following description will be focused on the points different from the first example.

  In the case of the rolling bearing unit to which the preload is applied, as described in Patent Document 8, the outer ring 1 is a component that determines the preload value in order to keep the preload value within a certain range. It is known to perform selective combination (matching) of the hub 2 and the rolling elements 3, 3 (see FIGS. 6, 9, 10, and 12). When such a selective combination is performed in step 1 (S1) of FIG. 3, the initial gap is determined in step 2 (S2) based on the dimensions of the above-described constituent members (outer ring 1, hub 2, rolling elements 3, 3). Is calculated, the preload clearance relating to the rolling bearing unit can be estimated from the relationship between the initial clearance and the completed clearance as shown in FIG.

  Therefore, the rolling bearing unit is assembled in step 3 (S3), and further, in step 4 (S4), if a preload is applied to the rolling bearing unit by tightening a nut or forming a caulking portion, the rolling bearing unit is in this state. The value of the preload applied to the bearing unit can be within a predetermined range predicted based on the selected combination. In this case, if the structure shown in FIGS. 6, 10, and 12 is used, the tightening torque of the nut is adjusted to a predetermined value (kept at a constant value), and the caulking portion is processed if the structure is shown in FIG. 9. The amount of change from the initial gap to the gap after completion is adjusted by adjusting the load at the time of holding (maintaining a constant value) (the amount of reduction of the gap due to tightening of the nut or the caulking process = the absolute value of the negative gap) (Increase amount) can be adjusted (restricted to a value determined by the initial gap value). The gap after completion can be estimated from the initial gap by keeping the amount of change within a certain range. Further, from the gap after completion, as shown in FIG. 5, the rigidity of the rolling bearing unit can be estimated from the relationship between the gap and the rigidity. Further, from this rigidity, the first example of the above-described embodiment can be estimated. From the equation (1), the preload applied to the rolling bearing unit can be estimated. In short, if the initial clearance is known, this preload can be estimated. Then, using the preload value estimated in this way, similarly to the case of the first example of the above embodiment, based on the phase difference ratio existing between the output signals of the sensors 6a and 6b. A gain for obtaining the axial load can be determined.

  Further, in the process of Steps 5 to 9 (corresponding to Steps 4 to 8 of the first example of the above embodiment), the axial load is based on the phase difference ratio in the same manner as the first example of the embodiment. Can be determined. Therefore, according to this example, it is not necessary to prepare a dedicated device and a dedicated process in order to obtain the zero point and gain, and the manufacturing cost of the rolling bearing unit with a physical quantity measuring device can be reduced.

  The steps according to this example will be briefly described step by step with reference to FIG. First, in Step 1, after measuring a plurality of dimensions of the outer ring 1, the hub 2, and the rolling elements 3 and 3 constituting the rolling bearing unit, the outer ring 1 and the hub 2 having appropriate dimensions are measured. And the rolling elements 3 and 3 are selected, and in step 3, the rolling bearing unit is assembled. At this time, prior to assembly, in step 2, based on the dimensions of the selected outer ring 1, hub 2, and each rolling element 3, 3, the initial clearance of the rolling bearing unit (nut tightening, caulking portion is processed). Calculate the previous gap. The value related to the initial clearance, which is information relating to the preload obtained here, is printed on the rolling bearing unit as the barcode, the two-dimensional barcode, etc., as in the first example of the embodiment described above. An electronic component such as a label or an IC tag on which this information is recorded is attached by being attached or tied with a thin string. Alternatively, it is possible to directly mark the rolling bearing unit. The information on the preload may be an initial gap or a preload value estimated from the initial gap.

  In this way, if information on the preload for the rolling bearing unit is obtained, the preload is actually applied to the rolling elements 3 and 3 by tightening the nuts or forming the caulking portions. . Thereafter, as in the case of the first example of the above embodiment, in step 6 (S6), an output inspection is performed to confirm the output signals of the sensors 6a and 6b, and in step 7 (S7), The initial phase difference ratio between the output signals of these sensors 6a and 6b is confirmed, and further information on the zero and gain is created. In step 8 (S8), this information is stored in the memory of the arithmetic unit. 9 (S9), a rolling bearing unit with a physical quantity measuring device is completed. If necessary, after tightening the nut or forming the caulking portion, the rigidity of the rolling bearing unit may be measured to determine whether the rolling bearing unit is good or bad.

  In the case of this example as described above, similarly to the case of the first example of the above-described embodiment, it is not necessary to prepare a dedicated device and a dedicated process in order to obtain the zero and the gain, and the physical quantity measurement is performed. The manufacturing cost of the rolling bearing unit with device can be reduced. Further, in the case of this example, since the outer ring 1, the hub 2, and the rolling elements 3, 3 constituting the rolling bearing unit are selectively combined, the initial clearance is kept within a narrow range, and the rolling bearing unit is extended. The value of the preload applied to can be regulated within a narrow range. If the preload value can be regulated within a narrow range in this way, the types of gain maps prepared for selection according to the preload value can be reduced. In particular, if the preload value falls within a sufficiently narrow range, only one type of gain map can be used (as in the invention described in claim 5, it is not necessary to select a gain map). Become).

  That is, it is only necessary to prepare one type of gain map, and it is not necessary to create a gain or apply a gain to the memory in the arithmetic unit, which was performed in steps 7 and 8 in FIG. The gain map can be written in advance in this computing unit, and it is only necessary to give the zero point information to this computing unit), and the inspection / shipment process in the production of the rolling bearing unit with the physical quantity measuring device is performed. Further, the manufacturing cost of the rolling bearing unit with a physical quantity measuring device can be further reduced. Further, if the gain map can be made of one type, the information and process to be given to the rolling bearing unit can be simplified, so that it can be produced at a lower cost. However, zero point inspection and provision are required individually.

  As described above, the operation of keeping the initial gap within a certain range is preferably performed by selecting the rolling elements 3 and 3 according to their outer diameters. By selecting the rolling elements 3 and 3 to regulate the initial gap, the outer ring 1 and the hub 2 can be arbitrarily combined, so that the yield does not deteriorate. In other words, when the outer ring 1 and the hub 2 are selectively combined, it cannot be used if there is a non-conforming part, and it is necessary to pool somewhere until a conforming part comes. No. 3 is not prone to such a problem because a large number of different outer diameters are prepared.

  In the above description, the rolling bearing unit for supporting the wheel has been described with a focus on the case of obtaining the axial load applied between the outer ring and the hub based on the phase difference ratio existing between the output signals of the pair of sensors. . However, the manufacturing method of the present invention can be applied not only to such a wheel support rolling bearing unit but also to a structure for measuring an external force applied to a double row rolling bearing unit for various industrial machines and machine tools. The types of external force to be measured are not limited to axial loads, but also include radial loads and moments. Furthermore, the sensor is not limited to a single pair, and may be a plurality of sets. As in the fourth example of the conventional structure shown in FIGS. 12 to 13 described above, there is only one sensor. Also good.

The flowchart which shows the manufacturing method of a rolling-bearing unit with a physical quantity measuring apparatus in order of a process regarding the 1st example of embodiment of this invention. The diagram which shows the relationship between the magnitude | size of the preload provided to each rolling element which comprises a rolling bearing unit, and the phase difference ratio produced between the output signals of a pair of sensor based on external force. The flowchart which shows the manufacturing method of a rolling-bearing unit with a physical-quantity measuring apparatus in order of a process regarding the 2nd example of embodiment of this invention. The graph which shows the relationship between the value of an initial stage gap, and the value of the gap after completion of assembly in the case of assembling a rolling bearing unit. The graph which shows the relationship between the value of the clearance after the completion of assembly of a rolling bearing unit, and the rigidity of this rolling bearing unit. Sectional drawing which shows the 1st example of a conventional structure. The figure which looked at a part of encoder incorporated in this 1st example from the diameter direction. The diagram for demonstrating the state from which the output signal of a pair of sensor changes based on an axial load. Sectional drawing which shows the 2nd example of a conventional structure. Sectional drawing which shows the 3rd example. The figure which looked at a part of encoder incorporated in this 3rd example from the diameter direction. Sectional drawing which shows the 4th example of a conventional structure. The figure which looked at a part of encoder incorporated in this 4th example from the diameter direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Hub 3 Rolling element 4, 4a-4c Encoder 5 Cover 6a, 6b Sensor 7 Sensor holder 8, 8a, 8b Through-hole 9, 9a, 9b Column part 10 First characteristic change part 11 Second characteristic change part

Claims (9)

A rolling bearing unit and a physical quantity measuring device;
Of these, the rolling bearing unit has a double-row stationary side raceway on the stationary side circumferential surface, and a stationary side raceway that does not rotate during use, and a rotational side circumferential surface that faces the stationary side circumferential surface in the radial direction. A plurality of rotation-side raceways that have double-row rotation-side tracks, and a rotation-side raceway that rotates during use, and a plurality of preloads for each row between the rotation-side raceways of both rows and the stationary-side raceways of both rows. And a rolling element provided so as to be able to roll freely in a state where
The physical quantity measuring device includes an encoder, at least one sensor, and a computing unit,
Of these, the encoder is supported and fixed concentrically with the rotation-side raceway by a part of the rotation-side raceway or a rotation member coupled and fixed concentrically with the rotation-side raceway. With the surface to be detected concentrically, and the characteristics of this surface to be detected are alternately changed in the circumferential direction.
The sensor is supported by a portion that does not rotate with the detection unit facing the detection surface of the encoder, and changes an output signal in response to a change in the characteristics of the detection surface.
Based on the output signal of the sensor, the calculator calculates the relative displacement between the stationary side raceway and the rotation side raceway and the external force acting between the stationary side raceway and the rotation side raceway. And having a function of calculating a physical quantity of at least one of
A method for manufacturing a rolling bearing unit with a physical quantity measuring device, comprising:
The degree to which the arithmetic unit calculates the physical quantity based on the output signal of the sensor, the degree to which the output signal or a value that changes according to the output signal changes, and the degree to which the physical quantity changes The characteristics relating to the rolling bearing unit that affect the gain, which is a relationship with the rolling bearing unit, are measured and recorded in the state of the rolling bearing unit alone, and the physical quantity measuring device combined with the rolling bearing unit is recorded. A method of manufacturing a rolling bearing unit with a physical quantity measuring device, wherein the method is recorded in a memory of a composing arithmetic unit.   The characteristic of the rolling bearing unit that affects the gain is the rigidity of this rolling bearing unit. By recording this rigidity or data related to this rigidity in the memory of the computing unit, the gain used by this computing unit can be determined. The method for manufacturing a rolling bearing unit with a physical quantity measuring device according to claim 1, which corresponds to the rigidity of the rolling bearing unit.   The characteristic of the rolling bearing unit that affects the gain is the preload of this rolling bearing unit. By recording this preload or data related to this preload in the memory of the calculator, the gain used by this calculator can be determined. The method for manufacturing a rolling bearing unit with a physical quantity measuring device according to claim 1, which corresponds to a preload of the rolling bearing unit.   The method for manufacturing a rolling bearing unit with a physical quantity measuring device according to claim 3, wherein the preload is obtained based on an initial clearance of the rolling bearing unit. A rolling bearing unit and a physical quantity measuring device;
Of these, the rolling bearing unit has a double-row stationary side raceway on the stationary side circumferential surface, and a stationary side raceway that does not rotate during use, and a rotational side circumferential surface that faces the stationary side circumferential surface in the radial direction. A plurality of rotation-side raceways that have double-row rotation-side tracks, and a rotation-side raceway that rotates during use, and a plurality of preloads for each row between the rotation-side raceways of both rows and the stationary-side raceways of both rows. And a rolling element provided so as to be able to roll freely in a state where
The physical quantity measuring device includes an encoder, at least one sensor, and a computing unit,
Of these, the encoder is supported and fixed concentrically with the rotation-side raceway by a part of the rotation-side raceway or a rotation member coupled and fixed concentrically with the rotation-side raceway. With the surface to be detected concentrically, and the characteristics of this surface to be detected are alternately changed in the circumferential direction.
The sensor is supported by a portion that does not rotate with the detection unit facing the detection surface of the encoder, and changes an output signal in response to a change in the characteristics of the detection surface.
Based on the output signal of the sensor, the calculator calculates the relative displacement between the stationary side raceway and the rotation side raceway and the external force acting between the stationary side raceway and the rotation side raceway. And having a function of calculating a physical quantity of at least one of
A method for manufacturing a rolling bearing unit with a physical quantity measuring device, comprising:
The degree to which the arithmetic unit calculates the physical quantity based on the output signal of the sensor, the degree to which the output signal or a value that changes according to the output signal changes, and the degree to which the physical quantity changes The preload applied to the rolling bearing unit so as to make the characteristics relating to the rolling bearing unit, which affect the gain, which are related to the above, coincide with the gain recorded in the memory of the arithmetic unit constituting the physical quantity measuring device A method for manufacturing a rolling bearing unit with a physical quantity measuring device, characterized in that adjustment is made.   The adjustment of the preload applied to the rolling bearing unit is performed by selecting one of these rolling elements having a predetermined diameter and installing it between a pair of stationary side track and rotation side track. Item 6. A method for manufacturing a rolling bearing unit with a physical quantity measuring device according to Item 5.   After combining the rolling bearing unit and the physical quantity measuring device, the external force that fluctuates in the operating state is not applied between the stationary bearing ring and the rotating bearing ring, and the two bearing rings are in a neutral position. The output signal of the sensor is taken into the arithmetic unit, and the sensor output signal in this state is recorded in the memory of the arithmetic unit as a zero point that is the value of this output signal when the physical quantity is in a neutral state. The manufacturing method of the rolling-bearing unit with a physical-quantity measuring apparatus as described in any one of claim | item 1 -6.   A rolling bearing unit is a wheel bearing rolling bearing unit for rotatably supporting a wheel on a suspension device of an automobile, and a stationary raceway is an outer ring that is supported and fixed to the suspension device when in use. The method for manufacturing a rolling bearing unit with a physical quantity measuring device according to any one of claims 1 to 7, wherein the raceway is a hub that rotates together with the wheel while the wheel is coupled and fixed.   The rolling bearing unit and physical quantity measuring device are combined, the outer ring is supported and fixed to the suspension device, the wheel is coupled and fixed to the hub, and the weight of the automobile is supported by the wheel on a flat surface. The sensor output signal is taken into the calculator while the outer wheel and the hub are in the neutral position without any external force changing between the hub and the driving state of the vehicle, and the sensor output signal in this state. The method of manufacturing a rolling bearing unit with a physical quantity measuring device according to claim 8, wherein: is recorded in a memory of an arithmetic unit as a zero point that is a value of the output signal when the physical quantity is in a neutral state.

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